Add from_canvas() to Surface for Wasm (#76)

Co-authored-by: Toniman575 <toniman575@gmail.com>

.github/workflows/ci.yml

@@ -118,3 +118,14 @@ jobs:
         !contains(matrix.platform.target, 'freebsd') &&
         !contains(matrix.platform.target, 'netbsd')
       run: cargo clippy --all-targets --target ${{ matrix.platform.target }} $OPTIONS --features $FEATURES -- -Dwarnings
+
+    - name: Lint with rustdoc
+      shell: bash
+      if: >
+        (matrix.rust_version == 'stable') &&
+        !contains(matrix.platform.options, '--no-default-features') &&
+        !((matrix.platform.os == 'ubuntu-latest') && contains(matrix.platform.target, 'i686')) &&
+        !contains(matrix.platform.target, 'redox') &&
+        !contains(matrix.platform.target, 'freebsd') &&
+        !contains(matrix.platform.target, 'netbsd')
+      run: cargo doc --no-deps --target ${{ matrix.platform.target }} $OPTIONS --features $FEATURES --document-private-items

Cargo.toml

@@ -85,3 +85,14 @@ rayon = "1.5.1"
 members = [
     "run-wasm",
 ]
+
+[package.metadata.docs.rs]
+all-features = true
+rustdoc-args = ["--cfg", "docsrs"]
+default-target = "x86_64-unknown-linux-gnu"
+targets = [
+    "x86_64-pc-windows-msvc",
+    "x86_64-apple-darwin",
+    "x86_64-unknown-linux-gnu",
+    "wasm32-unknown-unknown",
+]

src/lib.rs

@@ -1,6 +1,7 @@
 #![doc = include_str!("../README.md")]
 #![deny(unsafe_op_in_unsafe_fn)]
 #![warn(missing_docs)]
+#![cfg_attr(docsrs, feature(doc_auto_cfg))]
 
 #[cfg(target_os = "macos")]
 #[macro_use]
@@ -35,6 +36,9 @@ use raw_window_handle::{
     HasRawDisplayHandle, HasRawWindowHandle, RawDisplayHandle, RawWindowHandle,
 };
 
+#[cfg(target_arch = "wasm32")]
+pub use self::web::SurfaceExtWeb;
+
 /// An instance of this struct contains the platform-specific data that must be managed in order to
 /// write to a window on that platform.
 pub struct Context {

src/web.rs

@@ -11,6 +11,7 @@ use web_sys::ImageData;
 use crate::error::SwResultExt;
 use crate::SoftBufferError;
 use std::convert::TryInto;
+use std::marker::PhantomData;
 use std::num::NonZeroU32;
 
 /// Display implementation for the web platform.
@@ -56,6 +57,10 @@ impl WebImpl {
             // We already made sure this was a canvas in `querySelector`.
             .unchecked_into();
 
+        Self::from_canvas(canvas)
+    }
+
+    fn from_canvas(canvas: HtmlCanvasElement) -> Result<Self, SoftBufferError> {
         let ctx = canvas
             .get_context("2d")
             .ok()
@@ -96,6 +101,23 @@ impl WebImpl {
     }
 }
 
+/// Extension methods for the Wasm target on [`Surface`](crate::Surface).
+pub trait SurfaceExtWeb: Sized {
+    /// Creates a new instance of this struct, using the provided [`HtmlCanvasElement`].
+    fn from_canvas(canvas: HtmlCanvasElement) -> Result<Self, SoftBufferError>;
+}
+
+impl SurfaceExtWeb for crate::Surface {
+    fn from_canvas(canvas: HtmlCanvasElement) -> Result<Self, SoftBufferError> {
+        let imple = crate::SurfaceDispatch::Web(WebImpl::from_canvas(canvas)?);
+
+        Ok(Self {
+            surface_impl: Box::new(imple),
+            _marker: PhantomData,
+        })
+    }
+}
+
 pub struct BufferImpl<'a> {
     imp: &'a mut WebImpl,
 }